


Storm Front

by equilateral_asshat



Category: Gravity Falls
Genre: Archived From My Tumblr, F/M, pinecest - Freeform, pinescest - Freeform
Language: English
Status: Completed
Published: 2018-12-14
Updated: 2018-12-14
Packaged: 2019-09-17 20:49:09
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,021
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16981554
Author URL: https://archiveofourown.org/users/equilateral_asshat/pseuds/equilateral_asshat
Summary: A wicked storm outside makes it hard for Mabel to sleep, so she seeks shelter in Dipper's bed.





	Storm Front

Mabel chewed nervously on her lower lip, shuddering as another strong gust of wind shook the house enough for her to feel it. The storm outside had been raging for what seemed to be forever, to her, and it made it hard to sleep. Every flash of lightning, every howl of the wind and every boom of thunder made it too hard to keep her eyes shut. She stared around her bedroom at the army of stuffed animals, all watching her. Normally their vigilance would be reassuring, but every time lightning cut across the dark night sky, the faces seemed sinister.

 _Go away you stupid storm!_ she whined internally, glancing over at her cartoon-cat alarm clock, which displayed the time of 12:44AM. _Ugh, I’m never going to get to sleep at THIS rate._ With a groan she rolled over and buried her face in her pillows, trying to block out the noise from what seemed like a veritable typhoon. After a few minutes, she started to relax, and rolled back onto her side just in time for a mighty crash of lightning to streak through the sky so close it lit her whole bedroom for two seconds, throwing terrifying shadows this way and that before the ensuing thunderclap rattled her window. _NOPE NOPE NOPE._

Before she could process the thought of her actions, she was on her feet, clutching a pillow tightly to her chest as she marched over to her door, through it, and then across the hallway to her brother’s door and very quietly through it as well. _Mabel Pines, you haven’t shared a bed with your brother for 5 years, you’re practically an adult now, what are you doing?!_ she chided herself, hovering in his doorway, clad in naught but an old t-shirt and an equally worn pair of sweatpants, as she stared at his snoozing form. Then there was another flash, another house-shaking BOOM of thunder and before she could talk herself out of it, she was closing his door. _Hiding from the friggin’ storm, THAT’S what!_

She tiptoed carefully across the room, then stopped when she reached the edge of Dipper’s bed. She watched for what seemed like an eternity, taking the details in. His lips were slightly parted as he slept in an awkward sprawl, one arm over his bare chest and the other over his head. His bangs had flipped up in his sleep, revealing the dotted birthmark on his forehead that had earned him his nickname. His exposed stomach had a gentle dusting of fuzz that started at his bellybutton and trailed downwards into the waistband of his pajama pants. After awhile she realized she had been staring for what might have been TOO long, and she started to squirm anxiously, a blush crossing her features. What was all that, going on in the pit of her stomach? There shouldn’t be butterflies in there. Maybe she was just nervous about waking him up for something so trivial?

 _Ugh, he looks so peaceful,_ she thought with a smirk as a gentle snore buzzed through his nostrils. _Maybe we should just leave him alone so he can stay asle-_ The thought was cut short by another flash and bang, which caused her to audibly squeak in alarm before sitting on the edge of his bed, pillow still clung fiercely against her chest. A disturbed groan and shift in weight behind her told her it was too late to let him stay asleep now.

“M…mabes?” he croaked out, and she turned, head tilted and offering a nervous, sheepish grin. He was rubbing the sleep from his eyes as he sat up, one barely splitting open. “What are you doing in here? It’s-” he paused, glancing at his alarm clock, “-it’s ten past one in the morning.” Oh crud had she stood and stared for THAT long?!

“Couldn’t sleep,” she managed to whimper out, shifting nervously on the edge of his bed. As if on cue, to punctuate her statement, lightning brought another clap of thunder crashing down around the house. Just as fast as the lightning had lit the room, her face was pushed into his shoulder, her pillow dropped to hug around his midsection. She clung like that until she felt his hands pat her on the back and she realized he was hugging her. When she managed to peel herself away, she caught the sympathetic smile on his face. “C-can I, yanno, crash with my bro-bro for the night?”

With a grunt and a nod, he scooted closer to the wall and threw the covers back, patting the spot next to himself. Grabbing her pillow from the floor, she deposited it at the head of the bed and wiggled her way under the blankets. Pulling her brown tresses over one shoulder, she laid down with her back to her twin brother. “Thanks, Dippin’ dots.”

“D’ mention it,” he mumbled out, one hand reaching up to draw lazy circles against her back, right between her shoulder blades. A happy sigh escaped her as she finally felt herself relaxing, and eventually was off to sleep.

———  
———

When a flash of lightning forced her eyes open later, she stole a glance at her brother’s alarm clock. Only 4AM?! _Ugh, stupid freakin’ storm! Lemme sleeeeep._ When she tried to roll over to get comfortable, though, she noticed that sometime during the two hours and change of sleep she had managed to get, they had slightly tangled up. One of his legs were looped through hers, and his arm was draped over across her chest, the fingers of his hand gently brushing where her shirt had rode up to reveal her taut midsection. Feeling his touch against her bare skin made her shiver. _Mabes no, what are those feelings?! Quit getting all squirmy over your broheim sleep-spooning you._

She lay perfectly still for awhile, just listening to him breathing as she tried to will herself back to sleep. But sleep just wouldn’t come unless she could move, and to do that she’d have to undo the tangled pile of limps and torsos she and her twin had become. _Okay, girl, steady, steeeeaaady…_

First she slowly shifted her legs, bending one at the knee and straightening the other, the movements agonizingly slow until she felt his leg disengage. She exhaled a small sigh of relief, and then tried to wiggle her way into escaping his arm. However, as soon as her weight shifted, his grip tightened and he pulled her closer. Her chest froze as she drew a sharp breath, feeling every curve and surface of his body press into her from behind. And, she noticed with a gulp, every curve and surface meant _EVERY_ curve and surface, quite literally.

Oh sure, having a strong chest pushed into her shoulders wasn’t so bad, that was comforting! The way his flat stomach molded to the curve of her spine, that was cozy. But the way his thighs had pushed firmly up against her backside had brought something else with them. Something no sister should feel her brother pressing into her butt. _OhgodwhatdoIdo._ Even in her mind there were no spaces between the panicked words.

She gave a small wiggle, upper body trying to loosen his grip. _Please don’t wake up please don’t wake up!_ Just when it seemed like his grip was loosening up, he cuddled close again in his sleep. _Oh god it’s pushing right against me, why is it so hard?! Why is it so BIG?! And why does the thought of that make my downstairs mix-up go wild?!_

 _Okay Mabel, deep breaths, maybe he’ll roll over any moment now. Aaaany moment. Anytime._ These phrases repeated in her skull for what seemed like forever, but it seemed to be no more than wishful thinking. The storm raging outside was suddenly seeming very quiet compared to the storm inside her head. _Dipper, please move I don’t wanna wake you up like this you’ll probably die of shame! If I don’t first!_

For the next few minutes this odd game of cat and mouse continued, nothing between her rump and his wiener but two pair of pajama pants. Every time she tried to make room he would subconsciously scoot back up to meet her, or pull her back against himself. And every time his hips bumped up into hers again, that feeling in her tummy and between her legs grew until the two intermingled.

 _Ugh, fine! I have one hand free and if I’m gonna be stuck like this I might as well TRY and enjoy it, maybe it’ll even help me sleep._ With a defeated huff of breath, she managed to twist and wiggle until she slipped a hand under the waistband of her own pants, fingers crawling down until they brushed over her slickened sex. _Man, Mabes, after we get out of this we gotta have a talk with ourself about how having your bro grind into your butt with his sleepytime-boner got you THIS wet._

Her middle finger managed to quell that train of thought, the very tip of it gently circling her button and causing her breath to hitch temporarily. Her index and ring fingers, meanwhile, slid over her moistened lips, then spread them apart as her middle finger dove a little deeper, gently gliding past her clitoris and then bending to wiggle into herself. Her entire body locked up as soon as it was in there, half because she almost came then and there, and half because if she hadn’t forced herself still she would have ground back against her brother and that presumably large tent in his pajamas.

A ragged rush of breath escaped as she slowly forced herself to relax, fingers setting back to work. _Okay Mabel, c'mon, you can do this quietly,_ she willed herself as the first digit inside her was quickly joined by a second, the two rolling around against her inner walls. Every time they hit that perfect spot her chest caught, a tiny whimper rising in her throat. But she would slow herself down and continue to ride it out, determined to kill this squirmy sensation the best way she knew how.

 _Oh god, ohgod so close, c'mon Mabes don’t be loud!_ Biting her lower lip, her hips gave an instinctive roll, and she felt Dipper push back just as she hit the big-o. _Oh fuck!_ She wasn’t sure if the thought was from the climax she was currently trembling from, or the fact that she heard her brother inhale in a way that signified what she had dreaded most in this moment. “Nnnggh, Mabel what are you squirming around for, I’m trying to sl-”

She couldn’t tell what caused him to pause. Was it her ragged, uneven breathing? The fact that one of his hands had, right before he awoke, cupped a breast through her shirt and had a very noticeable nipple poking the palm? Or was it how her fingers audibly squelched out of her slit? Maybe the most obvious, about how he gave his hips a small wiggle and started putting two and two together in his head. His entire body went tense, and in that brief instant his member flexed against her fleece-clad rear end. Then, she wasn’t sure if it was involuntary or exploratory, but the hand on her breast gave a tiny, tender squeeze.

“So, uh, f-finding anything you like there?” The phrase was meant to be a joking little icebreaker, but the catch in her throat made it implicitly clear that she wasn’t telling him to stop. His hand moved in a heartbeat, and then his hips angled back and away.

“OhgodMabel, I’m so sorry I didn’t realize what I was doing in my sleep and-wait why were YOU being all squirmy?!” he hissed. She twisted her head around to try and catch his eye out of the corner of her own as she gulped. He was staring at her with nervous fear, and… was that anticipation she saw hiding under his eyes? She just took a wet finger and tapped his nose softly. He wrinkled his nose, and then his eyes went from half-awake panic to fully open terrified. “Why were you doing that in _MY BED_?!”

“Well if you must know,” she began, turning over to face him, a bit of anger rising in her tone, “Lightning woke me up and here I am, being held prisoner by my brother while our limbs tangle like discarded earbuds. So I get us most of the way untangled and then my loving, protective brother who was so kind to let me ride out the storm in his bed started to dry hump me with his big ole wang-doodle!” He started to talk but she stuck her finger-yep, that wet one from earlier!-against his open lips. Both to shut him up and for effect, she was on a roll here. “So, instead of deciding to be entirely weirded out by this unfolding of events-still sort of fighting to stay from being _totally_ weirded out-I decided to take advantage of the strange little tickles my belly was giving me and enjoy myself! It coulda helped me go back to sleep!”

He lay there, his eyes wider than she could have ever recalled. They darted from her own eyes, which were furrowed at him with a grumpy scowl on the rest of her burning face, to her finger, and back, almost pleading. Instantly her scowl melted away and she apologized with a sheepish little shrug as she retracted the finger.

“S-so, uh… Big? Really?” _Honestly, THAT’s the question you’re gonna ask Dipstick?!_ “I-I mean, uh, how did uh… how did all THAT get you so riled up you had to…” he said, motioning with a hand to try and fill in the blanks wordlessly. She was having none of it and just stared him down. He closed his eyes and groaned. “Mabel why were you buffin’ your muffin and grinding into my lap?”

“I told you, you had me on lockdown, I wanted to let you sleep, and YOU were grinding into MY butt!” she protested, sticking her tongue out. A few seconds of silence passed and she realized, at this point, he hadn’t tried to move any further away. Or told her to get out of his room. She quirked an eyebrow at him and he gulped a bit. “So… I’m noticing a distinct lack of making me leave for trespassing on your hospitality.”

“Pfff, what? What kind of brother would I be if I made my sister sleep out a storm alone?” he interjected, shrugging. Even in the dark of the room she could see his cheeks darken. “B-besides, you said I was the one doing the… the grindy stuff and all that…” One of his hands shifted up and scratched at the back of his neck. _He’s embarrassed, obviously, but he’s doing the ‘Uh oh I’ve been caught’ neckrub embarrassed? Okay Mabes, let’s see where this road takes us._

“So, you aren’t gonna get rid of me for canoodling myself in your arms?” He shook his head, faster than she’d anticipated. “Okay, but so long as we’re being frank about this stuff right now, I have one question.” He nodded nervously, gulping as one of her hands reached down, hidden by the covers, and tapped his tented pajamas right at the apex of the spire. “What exactly were you planning on doing with this?”

“M-MABEL!” he started, his voice rising in pitch which caused her to clamp a hand over his mouth and stare nervously at his door. His eyes followed hers, then after they nodded at one another she let go. “Mabes what are you doing?!”

“Weeelll, it feels like I’m exploring,” she remarked, fingers walking down the underside of his length through his pajamas, causing him to squirm and mutter a curse or two. “And it feels like you aren’t stopping me either.” He gulped, and with a staunch refusal to meet her eyes, shook his head. “Dipp?” His eyes screwed shut, tight. They even wrinkled at the corners. “Dipper, please look at me.” A deep breath, a heavy sigh, and finally his eyes opened to meet her own. “Do you want me to stop?” The question came from her own mouth, but it confused her how sad it sounded, how nervous and shaky it was.

Her brother shifted a bit closer, until his forehead brushed to hers, one hand lifting to brush over her cheek. “P-please, don’t stop,” he mumbled, his hips pushing up at her teasing fingers. She felt her face flush, and she was certain he could feel the heat radiating off of her features. The way he asked, the way his fingers gently wove through her hair, _Ugh Dipper, you’re not supposed to turn this control thing around on me by being so adorkable!_ As if to emphasize that point, she drug her nails over the underside of the taut fabric, which drew a sharp breath from her brother.

As much as she wanted to drag the situation out and tease, curiosity got the better of her and soon she’d hooked two fingers into his waistband, before pausing. She looked at her brother, watching his face. His eyes were closed peacefully, and his teeth were digging into his bottom lip which highlighted a tiny scar from his first shaving accident in the cutest possible way. When his eyes fluttered open and locked into hers, her heart pounded. The butterflies in her stomach had become a swarm of buzzing bees over the last minute or two. She licked her own lips, her mouth feeling horribly dry, and they both seemed to move at once, lips pushing together as her hand slid past his waistband and _HELLO._

His lips were rough, and a little bit of his stubble had a tiny bit of a sandpapery effect but in a good way? It was hard to put into words that she knew. All she knew was he was all she could smell, and hear, and taste. He had this musky scent that was like he’d absorbed the smoke of a campfire on a mild Autumn night. His lips were salty, and the way he moaned into the kiss caused those tummy-bees to go into raging hornet mode. And that was only half of what she had to process.

Down below her hand groped his pajamas out of the way and her fingers wrapped delicately around the base of his, well, LITTLE Dipper wasn’t a nickname option here. She could feel his heartbeat through it, and the skin was so warm, so firm in her hand. She squeaked against his lips when his hips arched towards the grope, her hand shifting to stroke up it, mentally recording the size. When she reached the summit her thumb did a little swirl, noting the bead of moisture she had just smeared over the more pliable flesh of his crown. “Damn, bro,” she muttered as their kiss broke, her hand giving another pump.

His body trembled, and his fingers clenched in her tresses as he whimpered, peppering her cheek and jawline with kisses that trailed to her neck and back up again, never lingering. Every kiss he planted was met with another stroke of her hand, and soon she felt his other hand spread his fingers over her stomach. He stared at her, silently asking permission, to which she nodded. In half a heartbeat his fingers had slipped down to find her lack of panties apparent. Her legs parted with a tremor of nervous excitement. _Oh my god, are we doing this? Is this happening or am I still aslee-NNNNYOOHGOD nope I’m awake, Those are definitely his fingers spelunking._

The rough skin of his fingers contrasted wonderfully to the smooth surface of her own, and my-oh-my did he know every little spot to hit. Her hand went faster as she buried her face against his neck, panting. “Ohfuck, oh fuck Dipperrrrrrr,” she moaned, biting down against his shoulder on the last syllable. Her hand sped up, determined to keep him right there where she was, teetering near the edge. He grunted, head tilting back as she bit, offering more of his neck and shoulder for a moment, but then he brushed his face up to hers, cheek to cheek as he panted into her ear. The way his hot breath washed over the burning skin of her ear threatened to push her into the lead. Coupled with the way his fingers danced expertly around her netherlips and her buzzer, she was certain she was going to get off without him until he whispered into her ear, letting her know how close he was. “M-me too, ooooohhhhh fuck bro,” she managed to sputter through clenched teeth, and suddenly her thighs clamped down on his hand.

The sensation of the swarm of rampaging insects in her midsection was replaced by a burning wave of euphoria, her eyes rolling back into her skull as her hips and shoulders trembled. She clamped her teeth down against his shoulder again, trying to muffle the rising scream in her throat. It would seem, much to her delight at the moment, her brother had a bit of a thing for being bitten, because that seemed to set him off, his girth swelling in her grasp before it pulsated and she felt her grip lubricated by the sudden addition of the spilling seed, and oh good lord when was it going to stop?!

They both lay, panting in the aftermath of their shared sin, each planting gentle kisses and whispering 'I love you’s to each other. Hearing him say that made her heart flutter, her face reddening again. After they could form coherent sentences, she slipped away, grabbing a wad of tissues from a box on his nightstand and handing him the box as she wiped her hand clean. He dutifully wiped himself clean as well, both of them having a bit of trouble looking each other in the eye for a moment.

“So…” she said, making eye contact first.

“So…?” _Ugh, Dipper, don’t make me say this out loud!_

“I… I’m sorry, if I pushed too hard, or anything. This was my fault,” she mumbled, feeling guilty. She then squeaked a tiny eep when she felt his lips press onto her forehead.

“H-hey, I asked you to keep going, I’m as much at fault.”

“Yeah but if I had just stayed in my room instead of coming in here and then diddling myself while you slept we wouldn’t have just-” she started up, and when she met his eyes her breath caught in her throat. He looked like a wounded animal. “I… do you regret it?”

“Not at all, Mabel. Do you?” She mulled that question over for a good thirty seconds or so before she came to a conclusion that shocked her. She shook her head and sighed. “Then stop apologizing.”

She nodded, still feeling sheepish as she cuddled up to her brother. “See you in the morning?” He just smiled and placed a loving kiss on her lips.

“See you in the morning.”

When Mabel woke up again, she noticed she had roughly ten minutes before her parents would be up to start their own morning routine. She wiggled quietly out of her brother’s grasp, reclaimed her pillow, and tiptoed to her own room. After another quick nap, she rose to shower, got dressed and half-waddled her way down the stairs to the kitchen where her parents and Dipper were all eating. After collecting a bowl and some cereal, she plopped down at the table next to her brother and began to eat as their father watched the morning weather report.

“…and it appears as though we’ll have another storm front moving in tonight, expect heavy winds and rain and possibly more lightning,” the weatherman reported. Their father’s grumbling about the forecast was lost on the twins as they shared a glance, a knowing grin, and a discreet wink. A happy little chill shot up Mabel’s back.

_I could stand to have another storm blow through._


End file.
